WO2009117420A1 - Multi-mode syringe - Google Patents

Abstract

A syringe cartridge includes a multi-mode device that defines at least two flow regimes having flow rates that differ m response to the same value of a vaπable The multi-mode device defines three flow paths The first flow path allows flow in only a first direction The second flow path is configured to allow flow below a predetermined rate in a second direction opposite the first direction in response to a variable having a value below a threshold The third path is configured to allow flow in the second direction at a rate higher than the predetermined rate in response to the variable reaching a value at or above the threshold.

Description

Attorney Docket No 19010 0002WO1

MULTI-MODE SYRINGE

This invention relates to a multi-mode syringe

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from U S Application Seπal No 61/037,263, filed on 5 March 17, 2008

BACKGROUND

The discomfort associated with the injection of anesthetics results from the pressure of the incoming fluid To minimize the discomfort, the anesthetic can be injected very slowly at first to numb the nerves and tissue at the point of the injection The fluids can then be o introduced at a higher rate without discomfort

Known devices include motor dπven syringes and microprocessor-controlled pumps For example, U S Patent No ₅,807,334 employs a motor built into the syringe to depress the plunger of a synnge cartridge Multiple gears provide slow flow rates and faster flow rates A number of devices employ a microprocessor-controlled pump to control anesthetic flow 5 rates hi one example of a microprocessor-controlled pump, the pump is in a unit distant from the hand held needle-bearing device Tubing is then necessary to transmit the fluid from the pump to the needle hi another example, U S Patent App Pub No 2001/0007327 Al employs repeated strokes on an altered synnge cartridge to meter the flow of anesthetic

SUMMARY 0 It is difficult for most practitioners to control the force applied to a conventional synnge well enough to successfully implement a pain-minimizing method The disclosed embodiments provide multiple modes of operation required for minimal injection discomfort while permitting the practitioner to continue using his/her familiar synnge The functional anesthetic capacity and external dimensions of the synnge remains unchanged 5 The modes can be directly controlled by the value(s) of one or more applied force related variables, for example, force, impact, impulse, or some combinations thereof The modes can be controlled by the value(s) of one or more pressure-related variables in a medium being dispensed resulting from the value of one or more of the applied force-related Attorney Docket No 19010 0002 WO 1

vaπables Below a pre-determined threshold value of the force-related or pressure-related vaπable, the flow rate of the medium is limited to a rate slow enough to maximize the patient' s comfort Once the pre-determmed threshold value of the force-related or pressure- related vaπable is reached, the mode changes to one of a conventional relationship between the force applied to the medium and the flow rate of the medium The multi-mode device may be included in a syringe cartridge or inserted into the head of a syringe to provide the multiple mode capability The device can employ, for example, mechanical, fluidic, and/or micro fluidic means to provide the multi-mode capability

A valve in the insert permits body fluids to enter the syringe cartridge when the practitioner applies a negative force to the syringe's plunger The practitioner can employ this to determine if a blood vessel or artery has been entered An opening m the insert provides very slow anesthetic flow rates until a larger valve opens, permitting a range of flow rates, including high flow rates The opening of the larger valve can be tnggered by reaching a threshold value of a pressure-related vaπable in the synnge cartπdge resulting from the value of a force-related vaπable applied to the syringe's plunger That value of the force- related variable is applied by the practitioner Alternatively, the opening of the larger valve can be triggered by the amount of anesthetic already dispensed or, directly or indirectly via an electric, magnetic, electronic, or other signal

According to one aspect, a synnge cartridge includes a housing configured for removable placement withm a syringe barrel, and a plunger, a seal, and a multi-mode device each attached to the housing for removable placement therewith

According to another aspect, a synnge includes a barrel for containing a medium, a plunger for applying a force-related variable to the medium, and a multi-mode device incorporated withm the barrel and/or attached to the plunger The multi-mode device defines at least two flow regimes having flow rates that differ m response to the same value of a vaπable In embodiments of this aspect, the synnge includes a housing withm the barrel for containing the medium, and the housing is configured for removable placement within the barrel

According to another aspect, a synnge includes a needle hilt, a barrel for containing a medium, a plunger for applying a force-related vaπable to the medium, and a multi-mode Attorney Docket No 19010-0002WO1

device incorporated within the needle hilt The multi-mode device defines at least two flow regimes having flow rates that differ in response to the same value of a variable

According to another aspect, a multi-mode syringe device includes a body sized for placement within a syringe The body defines three flow paths The first flow path mcludes a one-way valve configured to allow flow in only a first direction The second flow path is configured to allow flow below a predetermined rate in a second direction opposite the first direction in response to a variable having a value below a threshold The third path is configured to allow flow m the second direction at a rate higher than the predetermined rate m response to the variable reaching a value at or above the threshold Accordmg to another aspect, a method mcludes applying a force by hand to a syringe plunger to cause flow of medium from the syringe below a predetermined rate in a first flow regime in response to a variable having a value below a threshold, and applying a force by hand to the syringe plunger to cause a change m flow of medium from the syringe above the predetermined rate in a second flow regime in response to the variable reaching a value at or above the threshold The two flow regimes have flow rates that differ in response to the same value of the variable

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims

DESCRIPTION OF DRAWINGS

Fig 1 is an illustration of a multi-mode syringe

Fig 2 is a cross-sectional side view of a syringe cartridge including a multi-mode, vaπable flow device

Figs 3 A and 3B are perspective views of the multi-mode, vaπable flow device of Fig 2

Figs 3C and 3D are cross-sectional side views of the multi-mode, vaπable flow device of Fig 2

Fig 4 is a flow rate diagram for the multi-mode, vaπable flow device of Fig 2

Fig 5A is a perspective view of an alternative embodiment of a multi-mode, vaπable flow device Attorney Docket No 19010-0002WO1

Fig ₅B is a cross-sectional side view of the multi-mode, variable flow device of Fig ₅A

Figs 5C-5E are exploded side views of the multi-mode, variable flow device of Fig 5A Figs 6A and 6B are perspective views of an additional alternative embodiment of a multi-mode, variable flow device

Fig ₆C is a cross-sectional side view of the multi-mode, variable flow device of Figs ₆A and ₆B

Figs 7 A and 7B are perspective views of an additional alternative embodiment of a multi-mode, variable flow device

Fig 7C is a cross-sectional side view of the multi-mode, variable flow device of Figs 7A and 7B

Figs 8 and 9 illustrate typical injection profiles

Figs 1OA, 1OC, and 1OD are cross-sectional side views of a multi-mode, vaπable flow device associated with a plunger of a syringe cartridge

Fig 1 OB is a cross-sectional view through the multi-mode, vaπable flow device of Figs 1OA, 1OC, and 1OD

Fig 1OE is an exploded side view of the multi-mode, vaπable flow device of Figs 1OA, 1OC, and 1OD Figs 1 IA-11 C are cross-sectional side views of an alternative embodiment of a multi- mode, vanable flow device associated with a plunger of a syπnge cartridge

Figs 11D-11F are cross-sectional side views of an additional alternative embodiment of a multi-mode, vaπable flow device associated with a plunger of a syπnge cartπdge and isolated from the anesthetic fluid Figs 12A and 12C-12E are cross-sectional side views of an additional alternative embodiment of a multi-mode, vaπable flow device associated with a plunger of a syπnge cartπdge

Fig 12B is a top view of the multi-mode, vaπable flow device of Figs 12A and 12C- 12E Fig 13 is a syringe barrel including a multi-mode, vaπable flow device Attorney Docket No 19010 0002WO1

Fig 14 is a cross-sectional side view of an alternative configuration of the multi- mode, vaπable flow device of Fig 2

Fig 15A is a cross-sectional side view of an alternative embodiment of a multi-mode, variable flow device associated with a needle assembly of a syringe

5 Figs 15B is an exploded side views of the multi-mode, vaπable flow device of Fig

15A

Fig 15C is a proximal view of the multi-mode, vaπable flow device of Fig I₅A

Fig 15D is a distal view of the multi-mode, variable flow device of Fig 15A

Fig 16 is a cross-sectional side view of an alternative embodiment of a multi-mode, o vaπable flow device associated with a needle assembly of a syringe

Figs 17 A, 17D, and 17E are cross-sectional side views of an alternative embodiment of a multi-mode, vaπable flow device associated with a needle assembly of a syringe

Fig 17B is a proximal view of the multi-mode, vaπable flow device of Fig 17A, 17D, and 17E 5 Fig 17C is a distal view of the multi-mode, vaπable flow device of Fig 17A, 17D, and 17E

Figs 18 A, 18C, and 18D are cross-sectional side views of an alternative embodiment of a multi-mode, vaπable flow device associated with a needle assembly of a syπnge

Fig 18B is a cross-sectional view taken along line 18B-18B of Fig 18A without a0 flow restπction member

Fig 19A is a cross-sectional side view of an alternative embodiment of a multi-mode, variable flow device associated with a needle assembly of a syπnge

Figs 19B, 19C, and 19D are exploded side views of the multi-mode, vaπable flow device of Fig 19A 5 DETAILED DESCRIPTION

Referπng to Fig 1, a syringe assembly 10 includes a barrel 12, a plunger assembly 14 located at a first, proximal end 16 of the barrel 12, and a needle assembly 18 extending through a needle hilt 19 located at the opposite, distal end 20 of the barrel 12 The barrel 12 defines a chamber 22 within which is removably received a cartridge 24 having a housing 260 containing a medium 28 to be delivered to a patient, for example, anesthetic for use during a Attorney Docket No 19010-0002WO1

dental procedure Referring also to Fig 2, attached to the housing 26^" for removable placement therewith withm the barrel 12 is a plunger 30, a seal 32, and a multi-mode, variable flow device 34 Alternatively, a multi-mode device 35 can be positioned near, against, or integral to the plunger 30, or a multi-mode device 36 can be positioned in or 5 integral to the needle hilt 19 When assembled, the plunger assembly 14 pierces the plunger 30, and the needle assembly 18 pierces the seal 32 such that actuation of the plunger assembly 14 advances the cartridge plunger 30 forcing the medium 28 through the needle assembly 18 to the patient As discussed below, the multi-mode devices 34-36 act to automatically limit the initial flow rate of anesthetic into the patient to minimize the level of o pain experienced by the patient pnor to the onset of numbing

The multi-mode device 34 mcludes a cylindrical member 40 sized to be received withm a distal region 42 of the housing 26 by, for example, a friction fit, adhesive, and/or pms The distal region 42 of the housing 26 is closed off by the seal 32, which is secured in place by a cap 48 The cap 48 has an opening 50 through which the needle assembly 185 extends to puncture the seal 32

Referring to Figs 3 A and 3B, the cylindrical member 40 of the multi-mode device 34 defines a chamber 52 for delivery of anesthetic therethrough The cylindrical member 40 has a front, proximal face 54 defining an opemng 56 to the chamber 52 Across the opening 56 is a membrane 58 The membrane 58 defines a first openmg 60 having a diameter m the range0 of 5 to 50 micrometers The optimal value of the diameter of the first opening 60 withm this range depends on a number of variables including the cartridge plunger's fπction, the distance between the first opening 60 and the axis of the cartridge, the distance between the first openmg 60 and the back entrance of the needle, the thickness of the membrane 58, the maximum acceptable pressure at the site of injection, and the value chosen for the differential5 pressure across the membrane at the transition between the second and third phases, discussed below

The membrane 58 also defines a second opening 61 having a diameter about the same as or greater than the inner diameter of the needle of needle assembly 18, and includes a oneway valve 62 that, when closed, covers opening 61 The one-way valve 62 is attached to the0 membrane 58 by a hinge 66 and only allows flow through opening 61 in a reverse direction, arrow A As illustrated m Figs 3B and 3C, when the needle assembly 18 is attached to the Attorney Docket No 19010-0002WO1

barrel 12 piercing the seal 32, the needle assembly 18 extends into the chamber 52 with a sharp tip 64 of the needle assembly 18 positioned near the membrane ₅8 The membrane ₅8 distorts when a net forward pressure differential across membrane 58 is applied by the cartridge plunger 30 When the value of a net forward pressure-related variable across the membrane 58 is at or above a threshold, for example, 150 to 350 kPa, the membrane 58 moves against the sharp tip 64 of the needle assembly 18 and is punctured (Fig 3D) The sharp tip 64 tears the membrane 58 or penetrates through the membrane 58 depending on the characteristics and dimensions of the membrane 58 The membrane 58 can be perforated to predefine the shape of the tear and/or the pressure causing the tear The differential pressure across the membrane 58 at the transition from the second to third phase can vary outside this range depending upon the fπctional force applied by the cartridge plunger

The multi-mode device 34 defines three flow paths The first flow path is through one-way valve 62 when the operator applies a back force to the cartridge plunger 30 resulting in a net back pressure differential across membrane 58 The second flow path is through opemng 60, which allows flow m a forward direction, arrow B, when a vaπable, here the operator applied forward value of a force-related vaπable placed on the cartridge plunger 30 resulting in a pressure-related vaπable across membrane 58, is below the threshold The third flow path is through the punctured membrane 58, which begins when the operator applies a forward value of a force-related vaπable to the cartridge plunger 30 resulting m a pressure-related variable across membrane 58 at or above the threshold

There are thus three distinct possible phases of flow 1) reverse flow through the first flow path, which permits the operator to check for proper placement of the needle, 2) forward flow below a predetermined rate, for example, less than 1 cc per minute, when the applied pressure related variable across membrane 58 is below the threshold, which automatically enables the operator to numb the tissue while minimizing pain and discomfort to the patient, and 3) forward flow that can reach rates above the predetermined rate initiated by an applied pressure-related vaπable across membrane 58 at or above the threshold level, which permits the operator to complete the injection with the flow characteristics of the syπnge being that of a typical syπnge having a cartridge without a multi-mode device The forward force applied to the cartridge plunger 30 acts to produce a pressure differential across the membrane 58 to close the one-way valve 62 Attorney Docket No 19010 0002WO1

Referring to Fig 4, the flow regimes within the second and third phases 70, 72, respectively, differ For the same value of the vaπable, for example, the net applied force, the flow rate in the third phase 72 is higher than the flow rate in the second phase 70 Thus, the second phase 70 is not as responsive to the applied force as is the third phase The third phase 72 is limited by the characteristics of the needle assembly 18, as in a conventional syringe without a multi-mode device 34, whereas the second phase 70 is limited by the size of the opening 60 of the multi mode device 34 While the flow regimes within the second and third phases 70, 72, respectively, differ, they need not be linear as illustrated, but can vary non linearly within a phase Referring to Figs ₅A and 5B, in another alternative embodiment, a multi-mode device 300 includes a cylindrical member 302 defining a chamber 304 for delivery of anesthetic therethrough The multi-mode device 300 has a front, proximal face 306 defining an opening 308 to the chamber 304 Across the opemng 308 is a membrane 310 The membrane 310 defines an opemng 312 and an opemng 313 The flow of anesthetic through opening 313 can be blocked or unblocked by a bi-stable valve 314 The bi stable valve 314 is attached to the membrane 310 by a hinge 316 The bi-stable valve 314 is controlled by a valve opener 318 connected to a valve opener support frame 322, and a valve closer 320 connected to a valve closer support frame 324 The valve opener support frame 322 is attached to the inner wall of the chamber 304 and the valve closer support frame 324 is attached to the cylindrical member 302 The bi-stable valve 314 can move to a partially open position toward closer 320 under a back pressure resulting from an applied negative force, from which the valve will automatically close when the back pressure differential across the membrane 310 is reduced by the aspiration flow, and can move to a stable open position, as descπbed further below (Closer 320 can prevent the bi-stable valve from becoming stably open at this time ) The stable open position of the bi-stable valve 314 is achieved, for example, by an elastic band 326 (Fig ₅D) extending between the hinge 316 and the bi-stable valve 314

Before force is first applied to the cartridge plunger 30, the bi-stable valve 314 is closed (Fig ₅C) When the operator applies back force to the cartridge plunger 30, sufficient for it to move, a first flow path is created through the bi-stable valve 314, which is in its partially open position (Fig SD), that is, the valve has moved toward or up against closer 320 Attorney Docket No 19010-0002WO 1

but short of its stable open position When the back force ceases, the pressure differential across membrane 310 is reduced due to the aspiration flow, the valve 314 returns to the position of Fig 5C When the operator applies forward force to the cartridge plunger 30 resulting in a below a threshold pressure, the bi-stable valve 314 remains closed and the second flow path is through the opening 312 The third flow path is through the bi-stable valve 314 When the operator applies a forward force to the cartridge plunger 30 resulting in a forward value of a variable related to the pressure differential across membrane 310 at or above the threshold, the membrane 310 distorts and moves the bi-stable valve 314 against the valve opener 318 (Fig 5E) The valve opener 318 pushes the bi-stable valve 314 to a stably open mode Because the bi-stable valve 314 is stably open, it remains open after the pressure differential across membrane 310 is lessened and the membrane 310 returns to its original position To close the valve, the operator applies a negative force to the cartridge plunger 30 resulting in a negative value of a vaπable related to the pressure differential across membrane 310 such that the membrane 310 moves the bi-stable valve 314 against the valve closer 320 (Fig 5D) The valve closer 320 pushes the bi-stable valve 314 closed (Fig 5C) This returns the cartridge to a state where a below threshold forward cartridge plunger force will result m second phase response mode and a reverse cartridge plunger force will result in first phase fluid flow

The bi-stable valve can advantageously eliminate pressure differences between the two sides of the membrane 310 that can result from insertion of the cartridge 24 into the barrel 12 of the syringe assembly 10 during manufacture The burst of flow that occurs from triggering the third phase can be tailored by desigmng the bi-stable valve to open at a predefined rate The bi-stable valve can be designed to open slowly to reduce the tπgger flow, or the bi-stable valve can be completely removed or altered if a microfluidic circuit is used Figs 6A and 7A illustrate other configurations for the cylindrical member of the multi-mode device Flow regulation through the flow paths can be provided by the methods descπbed herein and by "fluidic" and "micro-fhudic" circuits These employ fluid dynamics to achieve analogs to electronic and micro-electronic circuitry employing and controlling the flow of fluids instead of electrons The holes and chambers for flow can number only 2 or 1, depending upon the implementation For example, a micro-fluidic circuit can perform the function of regulating all three phases and the transition between them Attorney Docket No 19010 0002WO1

Referring to Figs 6A-6C, in an alternative embodiment, a multi-mode device 100 includes a cylindrical member 101 defining a chamber 102 extending from the distal end 101a of the cylindrical member 101 partially through the multi-mode device 100 for delivery of anesthetic therethrough The multi-mode device 100 has a front, proximal face 104 defining three through holes, 106, 108, and 110, extending through the front face 104 to the chamber 102 for flow of anesthetic therethrough The three through holes can differ m diameter, and each of the through holes 106, 108, and 110 includes a means 106a, 108a, 118a to provide flow regulation through the flow paths, as discussed above

The first flow path is through the hole 106, which can be initially open or can be initially closed, opemng when negative pressure is applied across the multi-mode device 100 The second flow path is through the hole 108, which may be initially open, to assist in the back flow through hole 106, or initially closed, opening when a positive value of a vaπable related to the pressure differential across multi-mode device 100 below the threshold is applied The third flow path is through the opemng 110, which is initially closed, opening when a positive value of a vaπable related to the pressure differential across multi-mode device 100 at or above the threshold is applied While the flow paths through holes 108 and 110 are shown as distinct paths in Fig 6 A, the flow paths can be arranged such that the second flow path is a sub-part of the third flow path, for example, the second flow path is a partial opemng of a valve and the third flow path is further opening of the valve Likewise, the first flow path may be the same as the third, only in the opposite direction

Referring to Figs 7A-7C, in another alternative embodiment, a multi-mode device 200 mcludes a cylindrical member 220 defining a first chamber 202, a second chamber 204, and a fluid path 224 connecting the chambers 202, 204 The first chamber 202 extends at least partially through the multi-mode device 200 from the distal end 222, and the second chamber 204 extends partially through the multi-mode device 200 from the front, proximal face 206 The front face 206 defines two through holes of different diameters, 208 and 210 that extend from the front face 206 to the chamber 202 Each of the through holes 208 and 210 and chamber 204 mcludes a means 208a, 210a, 204a to provide flow regulation through the flow paths, as discussed above The embodiments illustrated in Figs 6A-6C and Figs, 7A-7C can be designed to be reversible from third phase operation back to first phase and/or second phase operation Attorney Docket No 19010 0002WO1

In embodiments m which the first flow path is covered by a membrane, the reverse flow is caused by the operator drawmg back on the plunger 30 stretching the membrane When the operator releases the negative force applied to the plunger 30, the membrane returns to its original shape, pushing at least some of the volume drawn m duπng aspiration 5 out of the cartridge

Referring to Fig 8, a typical injection profile over tune for a multi-mode device includes a first phase flow 74, followed by a second phase flow 70 The operator initiates the transition from the second phase to the third phase by increasing the value of vaπable related to the applied pressure across the multi-mode device to a value at or above the threshold at

10 76 This is followed by a bnef burst of flow at 78 m the third phase 72 due to the sudden pressure release, which is followed by a peπod of flow in the third phase 72 that is the standard cartridge flow response 80 over time

Referring to Fig 9, a typical injection profile over time for a membrane-based multi- mode device includes a first phase flow 2₅0 that mcludes a reverse flow stage 2₅1 and a

15 forward flow stage 256 due to rebound of the membrane covering the first flow path, followed by a second phase flow 252 The operator initiates the transition from the second phase to the third phase by increasing the vaπable related to the pressure across the membrane to a value at or above the threshold value at 258 This is followed by a bnef burst of flow at 259 in the third phase 254 due to the increased pressure differential across the

20 multi-mode device, which is followed by a peπod of flow in the third phase 254 that is the standard cartridge flow response 255 over time The burst of flow that occurs at the transition from the second phase to the third phase can be tailored by controlling/limiting the rate of membrane tearing, and/or can be reduced by reinforcing the area of the membrane where the needle penetrates the membrane The rebound and the transition burst of flow can 5 be eliminated m embodiments employing fluidic or micro-fiuidic components

Rather than positioning the multi mode device at the distal end of the cartridge, the multi-mode device can be positioned near, against, or integral to the cartridge plunger where the multi-mode device is directly acted upon by the cartridge plunger Referπng to Figs 1 OA and 1OB, a multi-mode device 400 is attached to the cartridge plunger 420 by a plunger

30 extension 406 The multi-mode device 400 includes a disk 450 defining at least one slot 452 (here four slots are shown) The disk 450 resists its motion duπng all phases due to the Attorney Docket No 19010 0002 WO 1

friction it has with the cartridge housing 26 Within each slot 452 is housed a bar 404 terminating in a friction head 402 The bars 404 are connected to the plunger extension 406 via hinges 408 and pms 414 When the operator moves the plunger 420, the plunger extension 406 is also moved and acts on the hmges 408 to slide the bars 404 within the slots 452 With the bars 404 positioned as shown in Fig 1 OA, with the friction heads 402 against the cartridge housing 26, there is a greater resistance to sliding of the plunger 420 within the cartridge housing 26 With the bars 404 positioned as shown in Figs 1OC and 10D, with the friction heads 402 spaced from the cartridge housing 26, there is less resistance to sliding of the plunger 420 within the cartridge housing 26 The multi mode device 400 defines three phases of flow The first phase allows flow m a reverse direction, arrow A, when the operator applies a back force to the cartridge plunger 420 Referring to Fig 1OC, as the operator applies back force to the cartridge plunger 420, the plunger extension 406 pulls the hmges 408, which slides each friction bar 404 inward such that friction heads 402 are spaced from the cartridge housing 26 The flow characteπstics of the syringe are now nearly identical to those of an unaltered cartridge

Referring again to Fig 1OA, the second phase allows flow in a forward direction, arrow B, when the operator applies a forward value of a force-related variable below the threshold value to the cartridge plunger 420 When the operator applies a forward value of the force related variable below the threshold value to the cartridge plunger 420, the plunger extension 406 pushes the hmges 408, which slides each friction bar 404 outward such that friction heads 402 move against the cartridge housing 26 (Fig 10A) In the second phase, the increased friction acts to reduce the flow rate m response to a given operator-applied force as compared to a standard cartridge Referring to Fig 10D, the third phase is entered when the operator applies a forward value of the force-related variable at or above the threshold to the cartridge plunger 420 As the forward value of the force-related variable applied to the cartridge plunger 420 reaches the threshold, the plunger extension 406 pushes the hmges 408 downward, which slides each friction bar 404 inward, such that the multi- mode device 400 enters the third phase that allows flows in a forward direction, arrow B and has properties nearly identical to an unaltered cartridge The friction heads 402 are made from, or are covered with, a material whose static and kinetic coefficients of friction are similar to or greater than those of the cartridge plunger Attorney Docket No 19010-0002 WOl

420 For example, the friction heads 402 can be made from the same material as the cartridge plunger 420

Referring to Fig 1 OE, the hinges 408 can include tabs 415 affixed to their inner ends 418, and the plunger extension 406 can include a tab block 416 affixed to it The tab block 416 of the plunger extension 406 acts against the rotation of the hinges 408 keeping the friction bars 404 pressed against the housing 26 to maintain the second flow rate phase over a broader range of forces applied to the cartridge plunger 420 Once the value of the forward force-related variable applied to the cartridge plunger 420 is at or greater than the threshold, the tabs 415 bend enough to allow the hmges 408 to rotate enough for the tabs 415 to clear the tab block 416, thereby pulling the friction bars 404 inward and allowing the start of the third phase

The multi-mode device 400 can be configured to easily make the transition from the third phase back to the second phase by applying a backward force to the cartridge plunger 420 Referring to Fig 1 OE, the tab block 416 is configured such that tabs 415 bend easily under the backward force allowing the hinges 408 to easily return the friction bars back to the state of second phase or first phase operation

The inner end 418 of hmge 408 moves inside a slot m plunger extension 406 and the opposite end of hinge 408 moves mside a slot in the end of friction block 404

Referring to Figs 1 IA-11C, a multi-mode device 500 is attached to a cartridge plunger 502 and includes a friction unit 504, friction bars 506, first phase tabs 508, second phase tabs 510, and a plunger extension 512 The tabs 508, 510 are connected to the plunger extension 512, and the friction unit 504 is shdably received within the cartridge housing 26 and surrounds the tabs 508, 510 The friction bars 506 are located m the slots 507 within the friction unit 504 When the tabs 510 are positioned against the friction bars 506 (Fig HB), the friction bars 506 are moved against the cartridge housing 26 and there is a greater resistance to sliding of the plunger 502 withm the cartridge housing 26 Friction unit 504 has large holes in its upper and lower surfaces, permitting the fluid to freely flow to and from the space between it and the lower surface of plunger 502 from and to the cavity withm friction unit 504 and to freely flow to and from the cavity in friction unit 504 from and to the main volume of the cartridge 26 The friction umt 504 resists its motion during all phases due to the friction it has with the cartridge housing 26 Attorney Docket No 19010 0002 WOl

The multi-mode device ₅00 defines three phases of flow The first phase allows flow in a reverse direction, arrow A, when the operator applies a back force to the cartridge plunger 502 As the operator applies back force to the cartridge plunger 502, the first phase tabs 508 pull the friction unit 504 in the reverse direction Duπng the first phase, the friction bars 506 are not against the housing 26 of the cartridge 24, and the syringe has flow characteristics nearly identical to an unaltered cartridge

Referring to Fig HB, the second phase allows flow in a forward direction, arrow B, when the operator applies a forward value of the force-related variable below the threshold value to the cartridge plunger 502 When the operator applies a below threshold forward value of the force-related variable to the cartridge plunger 502, the second phase tabs 510 push on the friction bars 506 pressing the friction bars 506 against the housing 26 of the cartridge 24, thereby increasing the friction of the cartridge plunger 502 and reducing the flow rate The second phase tabs 510 are deformed and lodged against the friction bars 506 for the duration of the second phase and under a wide range of combinations of forces, impulses, and/or impacts applied to the cartridge plunger 502

Referring to Fig 11 C, the third phase allows flow in a forward direction, arrow B, with a wide range of flow rates including a flow rate above the predetermined rate if the operator applies a forward value of the force-related variable at or above the threshold to the cartridge plunger 502 As the forward value of the force-related vaπable applied to the cartridge plunger 502 reaches the threshold, the second phase tabs 510 bend enough to clear the friction bars 506 and no longer apply force to the friction bars 506 such that the friction bars 506 are spaced from the housing 26 and the syringe has properties nearly identical to an unaltered cartridge

The upper surface of each second phase tab 510 is designed to have a low coefficient of friction such that the second phase tabs 510 quickly and easily slide upward when the operator applies a negative force to the plunger 502, returning the multi-mode device 500 to its first phase of operation (Fig 1 IA) from third phase operation Likewise, multi-mode device 500 may be easily returned to first phase operation from second phase operation

Figs 11 D-F illustrate a version of the embodiment of Figs 11 A-C where the braking mechanism is isolated from the anesthetic fluid This permits a wider range of materials to Attorney Docket No 19010-0002WO1

be used for that mechanism Also, the braking mechanism/cartridge occupies less volume m the cartridge

The pπmary differences between this version and that illustrated in Figs 11 A-C are that plunger extension ₅12a has been extended through the bottom of friction unit 504a, and a layer 509 of normal cartridge plunger diameter is affixed to the extended plunger extension 512a

The layer 509 isolates the braking mechanism from the anesthetic fluid The layer 509 can be used to pull back the friction unit 504a during the first phase (Fig HD) This eliminates the need for the tabs 508 Eliminating the tabs 508 permits a significant reduction in the length of the friction unit 504a This reduction more than compensates for the thickness of the layer 509 The second phase is illustrated in Fig 11 E, and the third phase is illustrated in Fig 11 F

The cartridge plunger 502a and the layer 509 define a fixed volume, so there is no need for fluid to flow in and out of this volume as the friction unit 504a moves inside of it Holes (not shown) are provided in the friction unit 504a to permit the fluid in the volume between the friction unit 504a and the cartridge plunger 502a to flow to and from the volume between the friction unit 504a and the layer 509 The fluid can be air If there is a potential danger of the air getting into the anesthetic liquid, the fluid can be sterilized water or more anesthetic fluid Similar adaptations can be made to the embodiments illustrated m Figs 10 and 12 to result in braking mechanisms enclosed within the cartridge plunger

Referring to Figs 12A-12E, in another alternative embodiment, a multi-mode device 600 located at but not affixed to the cartridge plunger 602 mcludes a ring 606 attached to at least one lock 608 (three locks being shown) by posts 612 Each lock 608 includes first and second segments 620, 622, respectively, connected by a center segment 624 Mounted between the locks 608 are three πng segments 604 which can move radially inward and outward Both ends 626, 628 of each πng segment 604 define a slot 630 The radial position of the πng segments 604 depends on the position of the lock segments 620, 622, 624 relative to the slots 630 The multi-mode device 600 defines an opening 610 for fluid flow therethrough Attorney Docket No 19010 0002WO1

In its initial state, the cartridge plunger 602 is located against the ring 606 (Fig 12A), and the lock segments 620, 622 are positioned between the πng segments 604 such that the ring segments are held in the outward radial position, compressed and fπctionally engaging the housing 26 The multi-mode device 600 defines three flow phases The first phase 5 allows flow in a reverse direction, arrow A, through the openmg 610 when the operator applies a back force to the cartridge plunger 602 During the first phase, the cartridge plunger 602 moves in a reverse direction, arrow A, in response to the force applied by the operator (Fig 12C), while the multi-mode device 600 remains stationary

Referring to Fig 12D, the second phase allows flow m a forward direction, arrow B,

10 through the openmg 610 when the operator applies a forward value of the force-related variable below the threshold to the cartridge plunger 602 In response to the forward force applied by the operator, the cartridge plunger 602 travels with the same properties as an unaltered cartridge until it reaches the πng 606 This permits the unrestricted return of the volume of fluid removed from the body during the first phase When the cartridge plunger

15 602 reaches the rmg 606 (Fig 12A), the cartridge plunger 602 and the multi mode device 600 travel together and the friction between the multi mode device 600 and the housmg 26 reduces the flow rate during the second phase

Referring to Fig 12E, the third phase allows flow in a forward direction, arrow B, through the openmg 610 with a wide range of flow rates including flow rate above the

20 predetermined rate when the operator applies a forward value of the force-related vaπable at or above the threshold to the cartridge plunger 602 As the forward value of the force-related variable applied to the cartridge plunger 602 reaches the threshold, the lock segments 620, 622 are displaced reducing the force applied by the ring segments 604 on the housing 26 such that the total friction applied by the cartridge plunger 602 and the πng segments 604 is about

25 the same as a conventional cartridge plunger A membrane or elastic band can be used to bias the nng segments 604 inward With the reduced friction from the πng segments 604, the syringe now has flow properties nearly identical to an unaltered cartπdge

Rather than employing a pressure-related value as the vanable that controls the transition from the second phase to the third phase, the variable can be the volume fluid of

30 delivered m the second phase The embodiment illustrated in Figs 12A- 12E can be configured to transition from second phase flow mode to third phase flow mode after a pre- Attorney Docket No 19010 0002WO1

determined volume of anesthetic has been delivered dunng the second phase In this variant, the friction imposed by the friction ring 600 does not allow the multi-mode device 600 to slide during the second phase Instead, as the plunger 602 presses on the friction ring 606, the plunger 602 causes the lock segments 620 and 622 to slide against the πng segments 604, until the plunger 620 goes into the slot 630 and the lock segment 622 goes into the volume of the cartridge The lengths of the lock segments 620, 622 and their interface with the πng segments 604 are configured such that the pre determined second phase volume is dispensed before the transition to the third phase

Likewise, the embodiment illustrated in Figs 11A-11C can be configured to transition from the second phase flow mode to the third phase flow mode after the delivery of a pre-determmed volume of anesthetic In this variant, the force of the second phase tabs against the friction bars prevents movement of friction umt ₅04 during the second phase Instead, the second phase tabs 510 slide along the inner surface 514 of the friction bars 506 That surface 514 on each friction bar 506 is long enough in the direction of the length of the cartridge such that the second phase tabs 510 remain engaged until the pre-determmed volume of second phase anesthetic is delivered When the second phase tabs 510 slide beyond that surface 514, the unit enters the third phase

Alternatively, the embodiments illustrated in Figs 11A-11C and 12A-12E, can be configured to transition from second phase flow mode to third phase flow mode after the delivery of a pre-determined volume of anesthetic or by reaching a value of a force related variable at, or above, a threshold value, whichever occurs first dunng a given second phase operation

Rather than incorporating a multi-mode device m a cartridge, a multi-mode device such as any of the embodiments described above can be incorporated into a syringe having a standard barrel and plunger arrangement Referring to Fig 13, a syringe 700 mcludes a barrel 704 for containing a medium, a plunger 706 for applying a force to the medium, and a multi mode device 702 incorporated withm the barrel 704 and/or the plunger 706 defining at least two flow rates that differ m response to the value of a vaπable, for example, pressure The multi-mode device 702 may be any one of the multi-mode devices described with reference to Figs 1 12 Attorney Docket No 19010-0002WO1

The multi-mode device can have a shape other than cylindrical For example, referring the Fig 14, a variable control device 34a flares proximally to mirror the shape of the inner wall of the cartridge

Rather than positioning the multi-mode device in a cartridge, a multi-mode device can be positioned withm the needle hilt 19 For example, referring to Figs 15A-15D, a multi-mode device 800 includes a flow body 802 sized to be received within a groove 23 of a bore 21 of the needle hilt 19 The flow body 802 defines first and second through holes 806 and 808 extending from a front, proximal face 804 to a back, distal face 810 of the flow body 802 for delivery of anesthetic therethrough perpendicular to the faces Four cut portions 812 form four lines on the front face 804 (Fig 1₅C) with solid corners and extend through the flow body 802 to form a square cut out on the distal face 810 (Fig I₅D)

The cut portions 812 are at an acute angle 813, e g , 4₅-70 degrees, from the back face 810 A removable plug 809 is located at the distal end 8I₅ of the second through hole 808 The plug 809 can be, e g , a region of the flow body 802 left when the second through hole 808 is created Alternatively, the plug 809 can be, e g , an insert fixed withm the second through hole 808 or a seal made by heatmg the region of the back face 810 surrounding the opening of the second through hole 808

The plug 809 covers the opening of the through hole 808 at the back face 810 until a net forward, B, pressure-related vaπable across the front face 804 reaches a threshold Once the net forward pressure-related vaπable across the front face 804 is at or above the threshold, the plug is removed, enabling flow through the second through hole 808 The diameter of the first through hole 806 depends on the maximum acceptable forward flow rate at the site of injection during the second phase The diameter of the second through hole 808 is about the same as or greater than the inner diameter of the needle of needle assembly 18 The multi-mode device 800 defines three flow paths The first flow path is m a backward direction, arrow A, through the cut portions 812 and the first through hole 806 when the operator applies a back force to the cartridge plunger 30 resulting m net back pressure across the flow body 802 The second flow path is through only the first through hole 806 m a forward direction, arrow B, when a variable, here the operator applied forward value of a force-related vaπable placed on the cartridge plunger 30 resulting in a pressure- related vanable across the flow body 802, is below a threshold In the second flow path, Attorney Docket No 19010-0002WO1

there is no flow through the cut portions 812 as the forward pressure-related variable across the flow body 802 closes the cut portions 812 due to the angle of the cut portions 812 into the flow body 802 The third flow path is through the first through hole 806 and the second through hole 808, which begins when the operator applies a forward value of a force-related vaπable on the front face 804 of the cartridge plunger 30 resulting in a pressure-related variable across the flow body 802 at or above the threshold resulting in removal of the plug 809 For example, the plug 809 is removed when the pressure-related vaπable across the front face 804 of the flow body 802 is at, for example, 150 to 350 kPa

Referring to Fig 16, rather than the through hole 808 having a constant diameter across the flow body 802, a multi-mode device 850 received withm the needle hilt 19 includes a pyramidal shaped bore 855 extending from the front face 804 that aids in limiting flow through the cut portions 812 in a forward direction, B When a forward pressure-related vaπable is applied across the front face 804 of the multi-mode device 850, the pyramidal shaped bore 855 results in a more perpendicular force being applied to the cut portions 812, keeping the cut portions 812 closed

Referring to 17A-17E, m another alternative embodiment, a multi-mode device 900 mcludes a flow body 902 that has holes through which flow is controlled by an annular πm 912 Flow body 902 defines a first through hole 904 and a plurality, e g , eight, second through holes 906 extending from a front, proximal face 908 to a back, distal face 910 of flow body 902 for delivery of anesthetic therethrough Extending from the back face 910 is the annular nm 912 that acts as a bi-stable valve covenng the second through holes 906 (Fig 17D) The annular πm 912 includes a one-way valve 914 extending through the center of the annular πm 912 and through flow body 902 to the front face 908 of the flow body 902 that allows flow in a backward, arrow A, direction Before a force is applied to the cartridge plunger 30, the annular rim 912 is curved such that outer regions 913 of the annular πm 912 abut against the back face 910, e g , the annular πm 912 is stably closed, to restπct flow through the second through holes 906 (Fig 17D) When the operator applies back force to the cartndge plunger 30, a first flow path is created through the one-way valve 914 and the first through hole 904 in a backward direction, arrow A That is, fluid flowing from the distal region of the one-way valve 914 forces the proximal regions 916 of the one-way valve 914 into wedge shaped bores 918 Attorney Docket No 19010 0002WO1

extending from the front face 908, thereby opening the one-way valve 914, as illustrated in Fig 17E When the back force ceases, the proximal region of the one-way valve 914 closes, as illustrated in Fig 17D When the operator applies a forward force to the cartridge plunger 30 that is below a threshold pressure, the outer regions 913 of the annular πm 912 are 5 maintained against the back face 910 to substantially prohibit the flow through the plurality of second through holes 906, and flow occurs through the second flow path defined by the first through hole 904 m a forward direction, arrow B, as illustrated in Fig 17D When the operator applies a forward force to the cartridge plunger 30 that is at or above the threshold, the outer regions 913 of the annular πm 912 move away from the face 910, e g , the annular

10 run 912 is stably open, allowing flow through the second through holes 906, in addition to the first through hole 904, as illustrated m Fig 17A To again restrict flow through the second through holes 906, the operator applies back force to the cartridge plunger 30 so that the outer regions 913 of the annular πm 912 move back against the face 910 This returns the multi-mode device 900 to a state where a reverse plunger force will result m a first phase

15 fluid flow and a below threshold forward cartridge force will result in a second phase fluid flow

Referring to 18A-18D, in another alternative embodiment, a multi-mode device 1000 includes a ball valve 1001 defining a chamber 1002 in the needle hilt 19 The multi-mode device 1000 includes a flexible disk 1004, back, proximal cushion 1006, front, distal cushion

20 1007, and a flow restπction member 1008 The flexible disk 1004 includes a first through hole 1009 having a diameter smaller than the diameter of the flow restπction member 1008 and a second through hole 1012 The chamber 1002 is defined to impede distortion of the flexible disk 1004 towards the distal end of the chamber 1002, but not impede distortion of the flexible disk 1004 in the opposite direction towards the proximal end of the chamber

25 1002

Before force is first applied to the cartridge plunger 30, flow restπction member 1008 is held against the back cushion 1006 by the flexible disk 1004 (Fig 18C) The flow restπction member 1008 covers the first through hole 1009 so that flow is restπcted through the first through hole 1009 When the operator applies back force to the cartridge plunger 30,

30 the fluid pressure applied to the flow restriction member 1008 in the backward direction, arrow A, forces the flow restπction member 1008 against the back cushion 1006, which Attorney Docket No 19010 0002WO1

distorts, allowing the flow restriction member 1008 to move apart from the flexible disk 1004 such that the flow restriction member 1008 does not completely cover the first through hole 1009 (Fig 18D) and a flow path is created through the first through hole 1009 and the second through hole 1012 When the back force ceases, the flow restriction member 1008 returns to its initial position and covers the first through hole 1009, as illustrated m Fig 18C When the operator applies a forward, arrow B, force to the cartridge plunger 30 that is below a threshold, a second flow path in the forward direction is created through the second through hole 1012 The flexible disk 1004 also distorts due to the pressure applied to it by the flow restriction member 1008, but the distortion is not great enough to allow the flow restπction member 1008 to pass through the first through hole 1009 When the operator applies a forward force to the cartridge plunger 30 that is at or above the threshold, the flexible disk 1004 distorts to allow the flow restπction member 1008 to pass through the first through hole 1009 mto the distal region 1014 of the chamber 1002, as illustrated m Fig 18A The fluid pressure applied to the flow restriction member 1008 in the forward direction, B, forces the flow restriction member 1008 against the front cushion 1007, which distorts, allowing the flow restriction member 1008 to move apart from the flexible disk 1004 such that the flow restπction member 1008 does not completely cover the first through hole 1009 (Fig 18 A) A third flow path is thus created through the first through hole 1009 and the second through hole 1012 m the forward direction, B To again restrict flow through the first through hole 1009, the operator ceases the forward force to the cartridge plunger 30 so that the flow restπction member 1008 covers the first through hole 1009 In addition, to return the multi mode device 1000 to a state where a below threshold forward cartridge plunger force results m the second phase response mode and a reverse cartπdge plunger force results in the first phase fluid flow, the operator applies back force to the cartπdge plunger 30 so that the flow restπction member 1008 returns to a proximal region 1020 of the chamber 1002 (Fig 18C) Less pressure is required to distort the flexible disk 1004 toward the proximal end of the chamber 1002 because, as discussed above, the chamber 1002 is defined not to impede the flexible disk 1004 toward the proximal end of the chamber 1002 Referπng to Figs 19A and 19B, rather than the ball valve 1001, a multi-mode device

1100 includes a bi-stable valve 1008 in a chamber 1102 m the needle hilt 19 for delivery of Attorney Docket No 19010 0002WO1

anesthetic therethrough Within the chamber 1102 is a membrane 1104 that defines a first through hole 110₅ and a second through hole 1106 The flow of anesthetic through the second through hole 1106 can be blocked or unblocked by a bi-stable valve 1108 The bistable valve 1108 is attached to the membrane 1104 by a hmge 1110 The bi-stable valve 1108 is controlled by the proximal end 1112 of the needle assembly 18 and the proximal wall

1103 of the chamber 1102 The bi-stable valve 1108 can move to a non-stable partially open position toward the proximal wall 1103 under a back pressure resulting from an applied back force The stable open position of the bi-stable valve 1108 is achieved, for example, by an elastic band 1114 (Fig 19D) extending between the hinge 1110 and the bi-stable valve 1104 Before force is first applied to the cartridge plunger 30, the bi-stable valve 1108 is closed When the operator applies back force to the cartridge plunger 30, sufficient for it to move, a first flow path is created through the second through hole 1106 as the bi-stable valve 1108 is in its partially open position (Fig 19D), that is, the valve has moved toward or up against the proximal wall 1103 but short of its stable open position When the back force ceases, the pressure differential across membrane 1104 is reduced due to flow in a backward direction, arrow A, and the bi-stable valve 1108 returns to its closed position (Fig 19C) When the operator applies forward force to the cartridge plunger 30 that is below a threshold pressure, the bi-stable valve 1108 remains closed and the second flow path is through the first through hole 11 OS (Fig 19C) When the operator applies a forward force to the cartridge plunger 30 resulting m a forward value of a vaπable related to the pressure differential across membrane 1104 that is at or above the threshold, the membrane 1104 distorts and moves the bi-stable valve 1108 against the proximal end 1112 of the needle assembly 18 to allow flow through the second through hole 1106 The proximal end 1112 of the needle assembly 18 pushes the bi-stable valve 1108 to a stably open mode Because the bi-stable valve 1108 is stably open, it remains open after the pressure differential across membrane 1104 is lessened and the membrane 1104 returns to its original position To close the bi-stable valve 1108, the operator applies a negative force to the cartridge plunger 30 resulting in a negative value of a vaπable related to the pressure differential across membrane 1104 such that the membrane

1104 moves the bi-stable valve 1108 against the proximal wall 1103 The proximal wall 1103 pushes the bi-stable valve 1108 closed This returns the multi mode device 1100 to a Attorney Docket No 19010 0002WO 1

state where a below threshold forward cartridge plunger force results in a second phase response mode and a reverse cartridge plunger force results in a first phase fluid flow The burst of flow that occurs from triggering the third phase can be tailored by designing the bi-stable valve 1108 to open at a pre defined rate The bi-stable valve 1108 can be designed to open slowly to reduce the trigger flow, or the bi-stable valve 1108 can be completely removed or altered if a microflmdic circuit is used

A number of embodiments of the invention have been descnbed Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention For example, referring to the embodiment of Figs 3A-3D, to alter the threshold pressure for the transition from the second phase to the third phase, the thickness of the membrane 58 can be varied with respect to its distance from the location where the back of the needle assembly penetrates the membrane At the location of penetration, a thinner membrane 58 is more easily penetrated and is more likely to tear, whereas a thicker membrane 58 is more likely to be penetrated without tearing In variants where the membrane 58 is designed for penetration without tearing, a backward force on the plunger can cause the back of the needle to be retracted from the membrane 58 This will cause a transition back to the second phase Outside the location of penetration, the thinner the membrane 58, the more the membrane distorts due to the pressure differential across membrane 58 resultmg from the force applied by the cartridge plunger 30 and the thicker the membrane 58, the less the membrane distorts due to the pressure differential across membrane 58 resulting from the force applied by the cartridge plunger 30

Rather than the seal 32 being a separate component from the multi-mode device, as shown m Fig 2, the seal can be incorporated into the distal end of the multi-mode device

Rather than the first through hole 80δ of Figs 15A-15D and 16 bemg located through a solid region of the flow body 802 perpendicular to the front face 804 or the back face 810 and parallel to the second through hole 808, the first through hole 806 can be located along one or more of the cut portions 812 Similarly, rather the second through hole 808 of Figs 15A-C and 16 being located through a solid region of the flow body 802 perpendicular to the front face 804 or the back face 810, the second through hole 808 can be located along one or more of the cut portions 812 Alternatively, the first through hole 806 can be replaced by a Attorney Docket No 19010-0002WO1

through hole through the plug 809 The diameter of the through hole through the plug 809 can be the same as or different from the diameter of the first through hole 806

Rather than the plug 809 of Figs 15 A-C being located at the distal end 815 of the flow body 802, the plug 809 can be located at the opposite, proximal end 816 of the flow body 802, covering the opening of the through hole 808 at the front face 804

Rather than the second through hole 1012 being defined through the flexible disk 1004, the second through hole 1012can also be defined through the flow restriction member 1008 Although a spherical shape is shown for the flow restπction member 1008, another shape, such as an ellipsoid shape Rather than including the back, proximal cushion 1006 and the front, distal cushion

1007 m the a multi-mode device 1000, the flow restriction member 1008 can be made of a resilient mateπal For example, the flow restπction member 1008 can distort if the pressure applied to the flow restπction member 1008 is at or greater than a threshold to allow the flow restπction member 1008 to move apart from the flexible disk 1004 such that the flow restπction member 1008 does not completely cover the first through hole 1009

Rather than the proximal wall ll03 of Figs 19A-19D controlling the bi-stable valve 1108, a distal end 1114 of needle assembly 1116 can control the bi-stable valve 1108 A proximal end of the needle assembly 1116 can penetrate the seal 32 of the cartridge 24 to allow flow into and out of the cartπdge 24 Although the multi mode devices 34, 300, 100, and 200 have been explained to be incorporated in the cartπdge 24, they can also be incorporated in the needle hilt 19 Similarly, although the multi-mode devices 800, 850, 900, 1000, and 1100 have been explained to be incorporated m the needle hilt 19, they can also be incorporated in the cartπdge 24 The multi mode devices described above may be made from any elastomer, such as a thermoplastic or thermoset elastomer Examples of suitable elastomers include Santoprene, ethylene propylene diene M-class polypropylene rubber (EPDM-PP), ethylene propylene diene M class rubber (EPDM), or silicone

The multi-mode device can mclude a needle guide m the chamber that receives the needle assembly 18 to direct the final location of the sharp tip 64 of the needle assembly 18 to improve reproducibility Attorney Docket No 19010-0002WO 1

In addition to the embodiments descπbed above, the multi-mode device can be built into any part of the syringe outside of the cartridge and needle assembly

Accordmgly, other embodiments are within the scope of the following claims

Claims

Attorney Docket No 19010 0002001

WHAT IS CLAIMED IS : I A multi-mode, syringe device, comprising a body sized for placement withm a syringe assembly, the body defining three flow paths, the body configured to form flow in only a first direction through the first flow path, the body configured to form flow below a predetermined rate in a second direction opposite the first direction m response to a variable having a value below a threshold through the second flow path, the body configured to form flow in the second direction at a rate higher than the predetermined rate in response to the vaπable reaching a value at or above the threshold through the third flow path

2 The multi-mode, syπnge device of claim 1 , wherein the second and third flow paths are configured to have flow rates that differ in response to the same value of the vaπable

3 The multi-mode, syπnge device of claim 1 , wherein the body is configured such that the vaπable is a force applied to a plunger of the syπnge assembly

4 The multi-mode, syπnge device of claim 1 , wherein the body compπses a membrane that defines a first openmg forming the first flow path and a second openmg forming the second flow path

5 The multi-mode, syπnge device of claim 4, wherein the body is configured such that the vaπable is a pressure differential across the membrane

6 The multi-mode, syπnge device of claim 4, wherein the first opening is larger than the second opening

7 The multi-mode, syringe device of claim 4, wherein the first openmg forms the third flow path Attorney Docket No 19010 0002WO1

8 The multi-mode, syringe device of claim 7, further comprising a bi-stable valve connected to the membrane for controlling flow through the first opening

9 The multi-mode, syringe device of claim 4, wherein the membrane defines a third opening forming the third flow path

10 The multi-mode, syringe device of claim 4, further composing a one-way valve connected to the membrane for controlling flow through the first opening, the one way valve forming flow only in the first direction

11 The multi-mode, syringe device of claim 4, further comprising a flow restπction member withm the body, wherein the flow restriction member is configured to abut against the membrane to restπct flow through the second opening in response to the variable having a value below the threshold, and to not contact the membrane in response to the vaπable reaching a value at or above the threshold

12 The multi-mode, syringe device of claim 1, wherein the first flow path is the same as the thud flow path

13 The multi-mode, syringe device of claim 1, wherein the body defines a first through hole forming the first flow path, a second through hole forming the second flow path, and a third through hole forming the third flow path

14 The multi-mode, syringe device of claim 13, further comprising a first valve located at an end of the first through hole, a second valve located at an end of the second through hole, and a third valve located at an end of the third through hole

I₅ The multi-mode, syringe device of claim 13, wherein the first through hole is smaller than the second through hole, and the second through hole is smaller than the third through hole Attorney Docket No 19010-0002WO1

16 The multi-mode, syringe device of claim 1 , wherein the body defines a first through hole forming the second flow path, and at least one second through hole forming the third flow path

17 The multi-mode, syringe device of claim 16, wherem the body defines at least one cut portion forming the first flow path, the at least one cut portion forming flow only in the first direction

18 The multi-mode, syringe device of claim 16, wherem the first through hole is smaller than the second through hole

19 The multi-mode, syringe device of claim 16, further comprising a flow restriction member located at an end of the second through hole, wherem the flow restπction member is configured to be removed in response to the variable reaching a value at or above the threshold

20 The multi-mode, syringe device of claim 16, further compπsing an annular rim extending from a face of the body, wherem outer regions of the annular rim are configured to abut against the face to restrict flow through the at least one second through hole in response to the vaπable having a value below the threshold, and to not contact the face in response to the vaπable reaching a value at or above the threshold

21 The multi-mode, syringe device of claim 16, wherein the body defines multiple second through holes forming the third flow path

22 The multi-mode, syringe device of claim 16, wherein the body defines a one- way valve forming the first flow path, the one-way valve forming flow only in the first direction

23 The multi-mode, syringe device of claim 1 , wherein the body comprises a friction unit attached to a plunger of the syringe assembly, wherein the fπction unit is Attorney Docket No 19010 0002WO 1

configured to contact a housing of the syringe assembly in response to the variable having a value below the threshold, and to not contact the housing in response to the vaπable reaching a value at or above the threshold

24 The multi mode, syringe device of claim 23, further comprising at least one hinge configured to attach the friction unit to the plunger

25 The multi-mode, syringe device of claim 1, wherein the body is configured to be received within a needle hilt of the syringe assembly

26 The multi-mode, syringe device of claim 1 , wherein the body is configured to be received withm a housing of the syringe assembly

27 The multi-mode, syringe device of claim 1 , wherein the body is configured to be attached to a plunger of the syringe assembly

28 A syringe assembly, comprising a syringe, and a body sized for placement within the syringe, the body defining three flow paths, the body configured to form flow m only a first direction through the first flow path, the body configured to form flow below a predetermined rate m a second direction opposite the first direction m response to a vaπable having a value below a threshold through the second flow path, the body configured to form flow in the second direction at a rate higher than the predetermined rate in response to the vaπable reaching a value at or above the threshold through the third flow path

29 A method, comprising applying a first force by hand to a syringe plunger to cause flow of a medium from a syringe assembly below a predetermined rate in a first flow regime in response to a vaπable having a value below a threshold, and Attorney Docket No 19010 0002 WOl

applying a second force by hand to the syringe plunger to cause a change in flow of medium from the syringe assembly above the predetermined rate m a second flow regime in response to the variable reaching a value at or above the threshold, wherein the two flow regimes have flow rates that differ in response to the same value of the vaπable

30 The method of claim 29, wherein applying the second force comprises applying a second force that is greater than the first force

31 The method of claim 29, wherein the variable comprises the force applied to the syringe plunger

32 The method of claim 29, wherein applying the first force causes flow of the medium through a first opemng of a membrane

33 The method of claim 32, wherein applying the second force causes flow of the medium through a second opemng of a membrane, the second opening being larger than the first opening

34 The method of claim 32, wherein applying the second force tears the membrane to allow flow of the medium through the tear

35 The method of claim 33, wherein applying the second force opens a bi-stable valve of the second opemng causing flow of the medium through the second opemng

36 The method of claim 33, wherein applying the second force causes a flow restriction member to pass through the second opening causmg flow of the medium through the second opening

37 The method of claim 29, wherein applying the first force causes flow of the medium through a first through hole of a body Attorney Docket No 19010 0002WO1

38 The method of claim 37, wherein applying the second force causes removal of a plug covering an end of a second through hole of the body causing flow of the medium through the second through hole

39 The method of claim 37, wherein applying the second force causes outer regions of an annular rim extending from the body to move away from the body causing flow of the medium through multiple second through holes of the body

40 The method of claim 29, wherein applying the second force causes a friction unit attached to the to the syringe plunger to be in contact with a housing of the syringe assembly, and applying the second force causes the friction unit out of contact with the housing of the syringe assembly